Methods for the production of air-sensitive phosphines such as, for example, trihydrocarbylphosphines having at least one aryl group and at least one alkyl or cycloalkyl group in the molecule, have been reported in the literature. Prior methods for the purification of reaction products containing desired forms of these phosphines have involved recrystallization in which ethanol was used as a solvent. However, these previous methods result in purity levels of no greater than 95% as measured by gas chromatography, purity levels which have proven to be inadequate in commercial applications of trihydrocarbylphosphines which are important catalyst components such as, e.g., neomenthyldiphenylphosphine.
Thus, a need exists for a way to produce highly pure (at least 97 mole percent as measured by .sup.31 P NMR analysis) neomenthyldiphenylphosphine. This invention is deemed to fulfill this important need in a surprisingly efficient and effective manner.